There are some enemies of smoothness, one is turning off Vsync in WinUAE before recording.

Once a perfect 50 fps recording is made, you can save it as a 50 or 25fps .mp4 that you can play on your computer. 50fps requires a good media player to not skip a single frame.

Your screen can then show it smoothly if you set it to a 50Hz mode. And reasonably smoothly, with shadowing (LCD)/slight stutter (CRT) if it has a 100Hz mode (same for a 75Hz playing the 25fps version).

On top of this, LCD screens add pixel shadowing if there is movement in the picture, causing the movement to be slightly blurry. With cheap LCDs and fast movement, quite noticably blurry.

And finally, standard codecs actively degrade picture quality in general (it's its job) and are made to compress movement within the picture. They have an especially tough time with the high contrast and high saturation colors used in games etc.

These are the steps you have to overcome (or, in most cases, find the best compromise with). The first step is to use a suitable codec (not a standard one) in WinUAE running at 320x256. Else it doesn't really matter what you do afterwards. ("Crap in, crap out")

If you google Recorded Amiga Games, you can download their video files and compare with their (newer) Youtube videos. They get pretty good results.

I looked at streaming video a few years ago, and 50 fps MP4 .ogg seemed quite OK then.

I think they recommended using the Techsmith codec (comes with Camtasia) for recording Amiga games, as it records in lossless quality.

I remember reading that in their forums and trying it out, and the quality of my videos improved dramatically.

I had no idea how to get smooth scrolling on Youtube though, so even the better quality videos (as compared to my old ones that is) still have very choppy and ugly scrolling.
The video files had much smoother scrolling, but when uploading them they degraded a lot in that regard... I wish I had looked up how to get better scrolling on there as I had no clue, I just uploaded the clips and that was it.

It's especially annoying in games like Shadow of the Beast, that is known for its silky smooth parallax scrolling.

EDIT - here is an example, I recorded Shadow of the Beast twice (a few years in between) as the old recording had such poor quality... I must have used something like xvid or so to record that one, I don't remember.[ Show youtube player ]

When I switched to the Techsmith codec, the picture quality became a lot better, but the scrolling still ended up horrible on Youtube, as I said.[ Show youtube player ]

No it can't, but 50fps video would still look closer to the original than a 25fps one (assuming of course that the game runs at 50fps). But it doesn't seem like there are many web services that allow you to maintain 50fps.

What makes things confusing is the concept of how many separate and discreet frames are displayed every second, verses how many times the frame is repeated every 1/24th, 1/25, or 1/30th of a second to match the refresh rate of the Television display.

TVs have their own screen refresh capabilities. A television's screen refresh rate is usually listed in the user manual or on the manufacturer's product web page.

The most common refresh rate for today's Televisions are 60hz for NTSC-based systems and 50hz for PAL-based systems. However, with the introduction of some Blu-ray Disc and HD-DVD players that can actually output a 24 frame per second video signal, instead of the traditional 30 frame per second video signal, new refresh rates are being implemented by some television display makers to accommodate these signals in the correct mathematical ratio.

If you have a TV with a 120hz refresh rate that is 1080p/24 compatible (1920 pixels across the screen vs 1080 pixels down the screen, with a 24 frame per second rate). The TV ends up displaying 24 separate frames every second, but repeats each frame according to the refresh rate of the TV. In the case of 120hz each frame would be displayed 5 times within each 24th of a second.

In other words, even with higher refresh rates, there are still only 24 separate frames displayed every second, but they may need to be displayed multiple times, depending on the refresh rate.

To display 24 frames per second on a TV with a 120hz refresh rate, each frame is repeated 5 times every 24th of a second.

To display 24 frames per second on a TV with a 72hz refresh rate, each frame is repeated 3 times every 24th of a second.

To display 30 frames per second on a TV with a 60 hz refresh rate, each frame is repeated 2 times every 30th of a second.

To display 25 frames per second on a TV with a 50 hz refresh rate (PAL Countries), each frame is repeated 2 times every 25th of a second.

To display 25 frames per second on a TV with a 100 hz refresh rate (PAL Countries), each frame is repeated 4 times every 25th of a second.

Based on this, the best results will be when we capture games in the 60hz NTSC mode and deinterlaced recordings by 60i-to-60p method (double deinterlacing). Playback will be smooth with common 60Hz PC-displays. But, yes, you still need the web services that allow you to playback 60fps videos.

Based on this, the best results will be when we capture games in the 60hz NTSC mode and deinterlaced recordings by 60i-to-60p method (double deinterlacing). Playback will be smooth with common 60Hz PC-displays. But, yes, you still need the web services that allow you to playback 60fps videos.

I'm guessing there are no web service that supports 50 or 60fps video upload and playback since the one I found closed down

a videogame to be smooth need at least 50 or 60 fps, for example on the Amiga putty squad ,chaos engine and Aladdin run at 25fps are not smooth
while Turrican series, assasin,zool 1 and 2 run at 50fps are smooth
I play some PC games at 120 fps on my monitor, some games allow it and that is great, super smooth,

videogames on youtube don't look smooth because despite you upload the video at 60fps they convert it degrading performance and quality, example you upload a DIVX video at 60fps they convert it to FLASH 30fps

What I tend to do is use overkill on the bitrates when uploading to youtube, taking into account youtube will always degrade the video somewhat. Another tip is to stick to constant bitrates rather than using minimum/maximum averages. You can give the illusion of having smooth scrolling using a blur effect on the motion but the trade off is the after images it leaves behind.

as a principle, all vides need to be deinterlaced (progressive as google deosn't do deinterlace and recode everything as interlace - this with resize create nasty pattern on video ) - Amiga can produce both types of video thus only one safe capture mode is 50/60fps full resolution (such as 736x568 for PAL, twice H res for SHires) - a bit overkill but... unavoidable as Amiga screen can have multiple resolution and different framerates and frame update speed.
btw you can cosnsider to upsacle video from Amiga even to 2160p: 3840x2160 or 1440p: 2560x1440 - sounds weird but this only way to obey google limitations (increase resolution by modulo 2 - remain area pad to fill resolution).
There is no need to loose time on encode quality.

Here is some
[ Show youtube player ]. I think the game segments look good enough, apart from the occasional blurring issues due to the 30 fps limit. I capture at the standard PAL resolution of 720x576 and then process depending on the type of game, but always bringing the FPS down to 25 before uploading.

Apart from my general information about what is going on, pandy71's advice is correct, or at least Youtube will mangle your video less if it's at least 720p. Getting that out of WinUAE is not possible I think, which is why I use Free Screen To Video and screen capture it instead. The alternative is to use the Recorded Amiga Games method I mention, but I'm not saying there's a guarantee your video won't get mangled.

You won't get Youtube to display a video with > 30 fps until something wonderful happens, i.e. Youtube webdevs must put in some work to support some 1980s quality 50/60Hz format and so will be able to encode to something other than the standard "something like 25 fps" FLV or 25/30 FPS MP4. Either way you'll be going with H264 for best results I think.